<?php

/*
	Question2Answer (c) Gideon Greenspan

	http://www.question2answer.org/

	
	File: qa-include/qa-image.php
	Version: See define()s at top of qa-include/qa-base.php
	Description: Outputs image for a specific blob at a specific size, caching as appropriate


	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.
	
	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	More about this license: http://www.question2answer.org/license.php
*/


//	Ensure no PHP errors are shown in the image data

@ini_set('display_errors', 0);

function qa_image_db_fail_handler()
{
    header('HTTP/1.1 500 Internal Server Error');
    qa_exit('error');
}


//	Load the Q2A base file which sets up a bunch of crucial stuff

require 'qa-base.php';

qa_report_process_stage('init_image');


//	Retrieve the scaled image from the cache if available

require_once QA_INCLUDE_DIR . 'qa-db-cache.php';

qa_db_connect('qa_image_db_fail_handler');

$blobid = qa_get('qa_blobid');
$size = (int)qa_get('qa_size');
$cachetype = 'i_' . $size;

$content = qa_db_cache_get($cachetype, $blobid); // see if we've cached the scaled down version

header('Cache-Control: max-age=2592000, public'); // allows browsers and proxies to cache images too

if (isset($content)) {
    header('Content-Type: image/jpeg');
    echo $content;

} else {
    require_once QA_INCLUDE_DIR . 'qa-app-options.php';
    require_once QA_INCLUDE_DIR . 'qa-app-blobs.php';
    require_once QA_INCLUDE_DIR . 'qa-util-image.php';


    //	Otherwise retrieve the raw image and scale as appropriate

    $blob = qa_read_blob($blobid);

    if (isset($blob)) {
        if ($size > 0)
            $content = qa_image_constrain_data($blob['content'], $width, $height, $size);
        else
            $content = $blob['content'];

        if (isset($content)) {
            header('Content-Type: image/jpeg');
            echo $content;

            if (strlen($content) && ($size > 0)) {
                $cachesizes = qa_get_options(array('avatar_profile_size', 'avatar_users_size', 'avatar_q_page_q_size', 'avatar_q_page_a_size', 'avatar_q_page_c_size', 'avatar_q_list_size'));
                // to prevent cache being filled with inappropriate sizes

                if (array_search($size, $cachesizes))
                    qa_db_cache_set($cachetype, $blobid, $content);
            }
        }
    }
}

qa_db_disconnect();


/*
	Omit PHP closing tag to help avoid accidental output
*/